July 27, 2009
I do alot of butterfly and dragonfly photography in the summer and was surprised by this butterfly when we came across it. I’m by no means an expert on identification, but it appeared to me to be an odd colored monarch. I looked for information online and read about nivosus or white monarchs. My understanding is that the color difference is caused by a recessive trait and affects less than 1% of the US monarch population. I think this is what I have here, can you confirm it for me? If this is rare it may have some interest for your readers.
Your Monarch Butterfly surely is a light individual, but it is not as white as the individual pictured on the Monarch Watch website illustrating the paper written by Lawrence Gibbs and Orley R. Taylor. That individual is truly white. We believe your individual may have a genetic predisposition for lightness, but we also believe it shows evidence of worn wings, perhaps due to old age and perhaps due to traveling long distances. As the wing scales are lost, the coloration of the butterfly appears more faded. It is also possible that this might be an intermediate coloration between the usual orange Monarch and the pale Nivosus Monarch. Perhaps an expert will be able to chime in and solve the question.
Thanks so much for your response. I followed up with your link to Monarch Watch and sent them an email and download of the photo. I received a response from them which also included some additional links within their site. Although they would need to see the actual specimen for 100% accuracy, they said it definitely appears to be a nivosus. After doing some reading on the site and looking at more photos, it appears there is a range of nivosus coloring such as the one I found to the very black and white which you noticed at the top of the article.